Method of making alloys of beryllium with plutonium and the like



slag.

United States Patent lVIETHOD OF MAKING ALLOYS 0F BERYLLIUM WITHPLUTONIUM AND THE LIKE Oliver J. 'C. Runnalls, Deep River, Ontario,Canada, as-

signor, by mesne assignments, to the United States of America asrepresented by the United States Atomic Energy Commission No Drawing.Application January 7, 1955 7 Serial No. 480,591

4 Claims. (Cl. 75-1223) This invention relates to the production ofalloys of beryllium with one or more of the metals uranium, plutonium,actinium, americium, curium, thorium and cerium. r

In accordance with the method of the invention a halide salt of themetal to be alloyed with the beryllium is heated in the presence ofberryllium, to reduce the halide to metal and cause the latter to alloydirectly with the beryllium. Although the heavy metal halides are morestable, thermodynamically, than the beryllium halides, the reducingreaction proceeds to completion it the berryllium halide product iscontinuously removed by vacuum distillation. The resulting alloy is,therefore, free of fluoride The pressure during the reactionispreferably maintained at about 10 5 mm. Hg, although other vacuumconditions may be employed. The mass is heated to a temperature of 1000C. to 1350" C. to insure reduction of the halide of the alloying metal.In each case suflicient beryllium is used to complete the'reduction andyet leave the desired amount of beryllium to be'alloyed with the reducedhalide metal.

The following examples are illustrative of the operation:

1. Preparation of plutonium-beryllium alloys 142 mg. of powderedplutonium fluoride PuF was mixed with 64 mg. of beryllium metal powder,and was placed in a berryllium oxide crucible. The-charge was heated invacuum at 1150 C. for 1 hour to reduce the plutonium fluoride with theberyllium to distill the beryllium fluoride BeF formed, and to alloy theplutonium with the beryllium. ,Since this alloy did not fuse below 1500C., it was hard sintered by raising the temperature to 1350 C. forfifteen minutes. The resulting alloy was crystalline, weighing 154 mg.and containing 70% plutonium. The plutonium yield in the reduction,therefore, was 94%.

2. Preparation of uranium-berryllium alloys 56.5 mg. of powdered uraniumfluoride UF, was mixed with 24.2 mg. of beryllium metal powder andplaced in a beryllium oxide crucible. The charge was heated in vacuumat.l200 C. for minutes to reduce the uranium fluoride with beryllium, todistill the beryllium fluoride BeF formed and to alloy the uranium withthe beryllium.

ice

2 The resulting alloy was crystalline, weighing 59.7 mg.

' and containing 69% uranium. The uranium yield in the reduction,therefore was 96%.

3. Preparation of actinium-beryllium alloys 15 me. (200 ,ug.) of Ac asAcCl was evaporated to dryness on oxalic acid along with 50 mg. ofuranium as a carrier. The actinium-uranium mixture was calcined to oxideat 600 .C. and fluorinated for 2 hours at 600 C. with a mixture ofanhydrous hydrogen fluoride and hydrogen. The resulting fluoride wasmixed with beryllium powder to produce a Be to Ac-l-U ratio of about 200to 1 in the final alloy. The mixture was heated at 5 10- mm. mercurypressure in a beryllium oxide crucible for 15 minutes at 1350 C. topermit the following reaction to go to completion.

The resulting alloy had melted and formed a, small sphere in the bottomof the crucible. During the heat treatment about 50% of the Ra distilledfrom the crucible but returned to the alloy with a half-life of 11.2days.

Alloys thus prepared of beryllium with plutonium, actinium, americiumand/ or curium are useful as neutron source materials. As these metalsare normally available in small quantities and are relatively ditficultto handle this method is particularly well adapted to providing suchalloys.

It will, be apparent that more than one of the alloying metals may beincorporated in the berryllium to produce, for example, an alloy ofberyllium, uranium and thorium.

The fluoride of the alloying metal is the preferred halide.

What is claimed is:

1. A method of producing alloys of beryllium with plutonium whichcomprises mixing halide of plutonium with beryllium and heating the massat 1000" C. to 1350 C. in vacuum to reduce the halide and alloy thereduced metal with beryllium.

2. The method defined in claim 1 wherein the beryllium halide formed isvolatilized from the reaction zone.

3. The method defined in claim 1 wherein the halide is fluoride.

4. A method of producing a plutonium-beryllium alloy which comprisesmixing plutonium fluoride with beryllium metal, heating the mass invacuum at about 1150 C. to reduce the fluoride and alloythe metals andremoving the volatile beryllium fluoride formed.

References Cited in the file of this patent UNITED STATES PATENTS1,648,954 Marden Nov. 15, 1927 2,574,627 Daane et al. Nov. 13, 19512,592,115 Carroll. Apr. 8, 1952 2,678,267 Saunders May 11, 19542,692,823 Cieslicki et al Oct. 26, 1954 2,809,887 Runnalls Oct. 15, 19572,826,495 Spedding et a1 Mar. 11, 1958

1. A METHOD OF PRODUCING ALLOYS OF BERYLLIUM WITH PLUTONIUM WHICHCOMPRISES MIXING HALIDE OF PLUTONIUM WITH BERYLLIUM AND HEATING THE MASSAT 1000*C. TO 1350* C. IN VACUUM TO REDUCE THE HALIDE AND ALLOY THEREDUCED METAL WITH BERYLIUM.